The correct answer is C. To maintain their own cultures.
Explanation
During the nineteenth century, the United States was a receiving country for immigrants from countries around the world, because during this time there was a deep instability caused by world wars and other factors. Therefore, these immigrants saw the United States as a suitable country to seek new life opportunities. Additionally, immigrants came to ethnic neighborhoods where communities from their country of origin or their culture lived, this phenomenon occurred because immigrants sought to maintain their cultures, preserving their customs and beliefs. Therefore, the correct answer is C. To maintain their own cultures.